Preventive programs have been offered for the most differing carcinomas since the middle of the fifties. Regarding cervical carcinomas, they are based mainly on the morphological and cytological examination of cytosmears of the cervix uteri, what is called the Pap test, which is made on the basis of gynecological routine examinations at regular intervals in women from the 20th year on. By means of the morphology of the cells, the smears are divided into various intensity degrees of dysplastic cellular changes. According to Pap I-V, these intensity degrees are referred to as normal, mild dysplasia, fairly serious dysplasia, serious dysplasia and invasive carcinoma, respectively. If the Pap test leads to a striking result, a small biopsy will be taken and subjected to a histopathologic examination, by which the kind and intensity of the dysplasia are determined and classified as cervical intraepithelial neoplasia (CINI-III).
In spite of all preventive programs, cervical carcinomas that lead to 400,000 new cases per year are the most frequent carcinomas in women. This is inter alia due to the fact that up to 30% of the results of the Pap test are false-negative.
In conventional screening for cervical carcinoma, swabs are used for detection of neoplastic lesions of the cervix uteri. In the screening procedure, different kinds of lesions have to be distinguished. Causes for lesions may for example be inflammations (due to infectious agents or physical or chemical damage) or preneoplastic and neoplastic changes. In morphological examinations the lesions of different characteristics are sophisticated to distinguish. Thus, for examination of swabs cytologists and pathologists have to be especially trained, and even experienced examiners have a high inter- and intra-observer variance in the assessment of a diagnosis based on cytological specimens. In general, the result of the examination is based upon the subjective interpretation of diagnostic criteria by the examining pathologist/cytologist. As a result, the rate of false positive and false negative results in the screening tests remains unsatisfying high.
However, the reproducibility of the examination results may be enhanced by the use of supporting molecular tools. Yet the problem with the preservation and preparation of the samples may not be overcome by just additionally using molecular markers. One further complication when performing cytological or histological examinations for screening purposes and especially when applying methods for the detection of molecular markers originates from strict precautions in preserving the samples from causing artifacts or improper results.
This is in part due to the instability of the cell-based morphological information and in part to the instability of the molecular markers to be detected during the tests. If the samples are not prepared, transported or stored in an appropriate manner, the cell-based information, or even the molecular information may be lost, or may be altered. So the diagnosis may be impossible, or may be prone to artifacts. For example, the interpretation of biopsies or cytological preparations is frequently made difficult or impossible by damaged (physically or bio-/chemically) cells. Furthermore regarding tissue samples or biopsies, the preservation of molecular constituents of the samples, which are subject to a rapid turnover, is sophisticated due to the time passing by until penetration of the total sample by appropriate preservatives.
As shown above, the morphologically supported diagnostic methods performed routinely in the art show two major disadvantages. Firstly, the methods are highly dependent on individual perception of the examiners. Secondly, the morphological information is quite sensitive to decay processes and thus to production of artifacts after preparation of the samples. Both aspects contribute to improper reproducibility of the results.
Therefore, it is the object of the present invention to provide a method by which cervical carcinomas can be diagnosed early and reliably. In addition, a differentiation should be possible by this method with respect to benign inflammatory or metaplastic changes from dysplastic preneoplasias. Moreover, the present invention provides methods for the detection of carcinomas on a biochemical basis from solubilized samples.